• Title, Summary, Keyword: COD reduction

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Removal of Heavy Metals from Acid Mine Drainage Using Sulfate Reducing Bacteria (황산염환원균을 이용한 폐광폐수의 중금속 제거)

  • Paik, Byeong Cheon;Kim, Kwang Bok
    • Journal of Korean Society of Water and Wastewater
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    • v.13 no.2
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    • pp.47-54
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    • 1999
  • SRB(Sulfate Reducing Bacteria) converts sulfate into sulfide using an organic carbon source as the electron donor. The sulfide formed precipitates the various metals present in the AMD (Acid Mine Drainage). This study is the fundamental research on heavy metal removal from AMD using SRB. Two completely mixed anaerobic reactors were operated for cultivation of SRB at the temperature of $30^{\circ}C$ and anaerobic batch reactors were used to evaluate the effects of carbon source, COD/sulfate($SO_4^=$) ratio and alkalinity on sulfate reduction rate and heavy metal removal efficiency. AMD used in this study was characterized by low pH 3.0 and 1000mg/l of sulfate and dissolved high concentration of heavy metals such as iron, cadmium, copper, zinc and lead. It was found that glucose was an organic carbon source better than acetate as the electron donor of SRB for sulfate reduction in AMD. Amount of sulfate reduction maximized at the COD(glucose)/sulfate ratio of 0.5 in the influent and then removal efficiencies of heavy metals were 97.5% of Cu, 100% of Pb, 100% of Cr, 49% of Mn, 98% of Zn, 100% Cd and 92.4% of Fe. Although sulfate reduction results in an increase in the alkalinity of the reactor, alkalinity of 1000mg/1 (as $CaCo_3$) should be should be added continuously to the anaerobic reactor in order to remove heavy metals from AMD.

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The Growth, Effect of COD-Reduction, and Flocculation Characteristics of Candida rugosa in Sugar Beet Stillages

  • Lee, Ki-Young
    • Journal of Microbiology and Biotechnology
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    • v.1 no.3
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    • pp.207-211
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    • 1991
  • Yeast fermentation at $40^{\circ}C$ was conducted for microbial protein production and COD reduction in three different sugar beet stiIlages by a thermo- and acid-tolerant yeast Candida rugosa isolated from East Africa. The assimilation proceedings of some main components such as protein, carbohydrate, total titrable acids and glycerol in stillages were observed with growth kinetics of the yeast. Most of glycerol and organic acids were rapidly assimilated at the beginning of the fermentation. Protein assimilation was slowly accelerated with the proceeding of fermentation time and its assimilation rate reached only 14.2%-28.4%. Though Candida rugosa was a flocculent yeast, the flocculation characteristics of the yeasts grown in three stillages were different from each other.

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Application of Ozone Oxidation to Reduce the Biological Treatment Time of Petrochemical Wastewater (석유화학 폐수의 생물학적 처리시간 단축을 위한 오존 산화의 적용)

  • Hong, Eun-Sik;Kim, Hyun-Suk;Lee, Sang-Hee;Chung, Jin-Suk;Shin, Eun-Woo;Ryu, Keun-Garp;Yoo, Ik-Keun
    • Journal of Korean Society of Environmental Engineers
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    • v.28 no.5
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    • pp.573-576
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    • 2006
  • The efficacy of integrated ozone oxidation-biodegradation treatment was examined in the treatment of petrochemical wastewater with a special focus on the overall treatment time. When raw wastewater with chemical oxygen demand(COD) of 70-80 mg/L was oxidized by ozone, approximately 20% of initial COD was removed in less than 1.5 min at a dosing rate of 400 mg $O_3/L{\cdot}h $. No further decrease in COD was observed for the extended ozone treatment up to 30 min. Biological treatment alone showed a rapid reduction of COD to 40-50 mg/L, subsequently resulting in the decreased rate of COD removal. Pre-treatment by ozone before biological treatment did not significantly affect the specific rate of COD removal in a biological treatment. When ozone oxidation followed biological treatment, the extent of COD removal by ozone oxidation was greater compared to that of biologically-treated wastewater for a shorter time. Taken together, it was decided that the biological treatment time could be reduced if the treatment processes of concern will be properly arranged.

Growth of Yeasts in Alcohol Distiller′s Waste of Dried Sweet Potato for Single-cell Protein Production and BOD Reduction (절간고구마원료 주정폐액을 이용한 단세포단백질의 생산 및 폐액의 BOD제거)

  • 이형춘;구영조;민병용;이홍근
    • Microbiology and Biotechnology Letters
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    • v.10 no.2
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    • pp.95-100
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    • 1982
  • Torulopsis candida FRI YA-15, a selected yeast, was cultivated in alcohol distiller's waste-filtrate of dried sweet potato for microbial protein production and BOD reduction. The General composition of waste-filterate was BOD$_{5}$ 15700 ppm, COD 36800 ppm, reducing sugar 3300 ppm, total nitrogen 910 ppm, total solids 51800 ppm and ash 390 ppm. The pH of waste was 3.85. The yield to the medium of T. candida cultivated in shake-flask at $25^{\circ}C$ for 48 hrs was 3.38g/$\ell$ and effectiveness in reducing BOD$_{5}$ and COD of waste was 38.9% and 31.8%, respectively. In batch cultivation using 3 $\ell$-jar fermenter, maximum yield to the medium reached 3.2g/$\ell$after 28 hrs cultivation under the condition of temperature 35$^{\circ}C$, initial pH 4.0, aeration rate 2vvm, agitation speed 100rpm. Dry yeast was composed of crude protein 47.98% and ash 5.23%.

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Effects of Elutriating Rates for Elutriated Acid Fermentation of Food Waste (음식물쓰레기 세정산발효공정에서 세정율의 영향)

  • Kwon, Koo-Ho;Lee, Sang-Hyub;Min, Kyung-Sok
    • Journal of Korean Society on Water Environment
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    • v.24 no.2
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    • pp.201-205
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    • 2008
  • The korean government started to ban the sanitary landfill of food wastes as of 2005. The radical change of policy is primarily due to the limited landfill site, but aimed to promote not only to reduce the food waste production but also to enhance the reuse and recycle. The performance of elutriated acid fermentation to evaluate the effects of elutriating ratios was investigated. The fermenters were operated with elutriating water to food waste volumetric ratio of 2, 1, 0.5 and 0.25. Initial pH of elutriating water was set for 9 based on the pH effects study. The cumulative amounts of SCOD production rate were $0.34gSCOD/gVS_i$, $0.45gSCOD/gVS_i$, $0.26gSCOD/gVS_i$ and $0.28gSCOD/gVS_i$ with the ratios of 2, 1, 0.5 and 0.25, respectively. The cumulative productions of VFAs were 0.12 gVFAs as $COD/gVS_i$, 0.28 gVFAs as $COD/gVS_i$, 0.21 gVFAs as $COD/gVS_i$ and 0.14 gVFAs as $COD/gVS_i$ with the ratios of 2, 1, 0.5 and 0.25, respectively. The volume reduction were 58%, 52%, 45% and 47% with the ratios of 2, 1, 0.5 and 0.25, respectively.

Prediction of Water Quality Improvement by using Ecological Modelling in Busan Coastal Area (생태계 모델링을 이용한 부산연안해역 수질개선 예측)

  • Jung, Woo-Sung;Kim, Jin-ho;Kim, Dong-Myung
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.5
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    • pp.524-531
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    • 2017
  • Water quality improvement was predicted by using ecological modelling with reference to reduced load pollutants in the Busan coastal area. The results showed appreciable improvement in water quality at Suyeong Bay and Nakdong Estuary but little improvement in water quality from the central to eastern regions, except in Suyeong Bay by COD concentration. There were also similar results for T-N and T-P, because the Busan coastal area has a more open boundary than the other bays in the South Sea of Korea, resulting in a fast flow rate. The reducted COD load was less than that found in other coastal areas. Also, the reduction rate of the total load was less than that of other coastal areas in terms of water quality improvement. Applying the reduction load estimated in this study, it should be possible to improve the water quality of Suyeong Bay and Nakdong Estuary.

Study for the comparative treatment method of industrial wastewater using coagulant and H.V.G (응집제와 정전기 수처리장치에 의한 산업폐수의 비교처리법에 관한 연구)

  • 김재용;정상섭;정성권
    • Journal of environmental and Sanitary engineering
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    • v.18 no.4
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    • pp.1-5
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    • 2003
  • For studying out the method of the effective purification of waste waters such as dying, paper pulp and plating wastewater, we measured the COD removal efficiency, color and turbidity of those pollutants by the physical and chemical method using the Inorganic Coagulating Agent (CM, RM) and a High Voltage Generator. The COD removal efficiency measured when applying the Inorganic Coagulating Agent (CM, RM) was mush higher than that using the Existing Coagulating Agent In addition to, when using those two methods above mentioned at the same time, both the COD removal efficiency and the reduction-effect of the inserting quantities of Coagulating Agent were higher than those were used singly. The system using both an Inorganic Coagulating Agent and a High Voltage Generator will be useful in various fields of wastewater treatment.

Estimation of Contribution Ratio and Community Sewerage Treatment Efficiency by using Advanced Sewage Treatment in the Basin of Hongcheon-river (홍천강 유역의 하수고도처리를 적용한 마을하수처리 효율 및 기여율 평가)

  • Park, Soo-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.7
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    • pp.3570-3576
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    • 2013
  • This paper calculated advanced sewage treatment efficiency and reduction pollution loads to estimation contribution ratio of for community sewerage in Hongcheon-gun County. The A2/O and SBR methods showed overall high treatment efficiency of 95% and 94% respectively, and SS was 80%. On the other hand, T-N and T-P showed relatively low processing efficiency of 56% and 60% respectively, but it was observed that SS showed high 96% in the MBR method. Next, by the result of yearly water change analysis on water quality of Hongcheon River which is the discharge river of community sewerage, it was observed that water quality was greatly deteriorated by COD, T-N and T-P. However, installation and operation of community sewerage showed high pollution load reduction in general water quality item by more than 80%, and in T-N and T-P by 58% and 68% respectively. It is expected that community sewerage will greatly contribute in water quality improvement of Hongcheon River.

Effects of Oxidation Reduction Potential and Organic Compounds on Anammox Reaction in Batch Cultures

  • Viet, Truong Nguyen;Behera, Shishir Kumar;Kim, Ji-Won;Park, Hung-Suck
    • Environmental Engineering Research
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    • v.13 no.4
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    • pp.210-215
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    • 2008
  • The present study investigates the effect of oxidation-reduction potential (ORP) and organic compounds on specific anaerobic ammonium oxidation activity (SAA) using batch experiments. The batch tests were based on the measurement of nitrogen gas production. The relationship between ORP and dissolved oxygen (DO) concentration was found to be ORP (mV) = 160.38 + 68 log [$O_2$], where [$O_2$] is the DO concentration in mg/L. The linear relationship obtained between ORP and SAA ($R^2$ = 0.99) clearly demonstrated that ORP can be employed as an operational parameter in the Anammox process. At ORP value of -110 mV, the SAA was $0.272{\pm}0.03\;g\;N_2-N\;(g\;VSS)^{-1}\;d^{-1}$. The investigation also revealed inhibitory effect of glucose on the SAA while acetate concentration up to 640 mg COD/L (corresponding to 10 mM) had stimulating effect on the SAA. However, acetate concentration beyond 640 mg COD/L had inhibitory effect on the Anammox activity. The results indicated that nitrogen rich wastewaters containing low level organic matter could be better treated by Anammox microorganisms in real-world conditions after some acidification process.

Fenton난s Reagent Oxidation of Refractory Organics in Petrochemical Plant Effluent (석유화학공장 방류수내 난분해성 유기물의 Fenton 산화처리)

  • Lee, Kyu-Hoon;Jung, Dae-Young;Park, Tae-Joo
    • Journal of Environmental Science International
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    • v.5 no.1
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    • pp.51-59
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    • 1996
  • The purpose of this study was to evaluate the partial oxidation of the biological treatment plant effluents using Fenton's reagent as a pretreatment step prior to a tertiary biological oxidation of these effluents. Fenton's reagent was evaluated as a pretreatment process for inhibitory or refractory organics. Based on the Fenton oxidation system, the petrochemical wastewater treatment plant effluent was shown to have significant improvement in toxicity after oxidation with hydrogen peroxide. For example, at ranee of 42 ∼ 184 mg/L COD of petrochemical plant effluents, the COD removal efficiencies were from 38.2% to 60.1% after reaction with hydrogen peroxide 200 mg/L and Fe2+ 100 mg/L and reaction time was 30 minutes. The total TOC reduction were about 15.8∼22.4% with same test condition and difference between the overall removal rate and BOD/COD ratio after Fenton's oxidation estabilished in the biodegradation and otherwise meets the discharge standard or reuse for cooling tower make-up water.

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